Earthenware tests 18/2

Out of the kiln this morning a number of Earthenware cone 04 glaze tests.
I'm still just trying to find successful base glazes, retesting some of the recipes I've tried before to make a base line for revisions.

All were fired to 1080 degrees Celcius on Keanes Earthenware tiles bisque fired to cone 04.

Worthington Clear 
EW cone 04

Gerstley borate     55%
Eckalite                30
Silica                    15

Results
Very clear glaze, some bubbles in suspension in thickest parts.




ABEM 
cone 04

Frit 3124               50
Eckalite                15.65
Whiting                16.65
Silica                    17.75
Total                            5

Results
Nice smooth matte glaze

EB* 
clear EW, cone 04

Frit 4131              83.3
Eckalite               16.6
* batches 2 and 3 combined and whizzed up to be smoother

Results
This seems quite matte even though its a clear recipe. Much better results from first try when I must have put incorrect amounts in. Whizzed up. Need to buy a sieve.




Julie's Satin
cone 04

Whiting                   17
Gerstley borate        27
Lithium carbonate     6
Nepheline syenite      4
Eckalite                    12
Silica                        34

Results
This glaze is still cracking. Which is a pity because I like the quality of its matte surface.
Will maybe try to modify it though I have tried before with no improvement.





Satin Base SB

Results
This is the old batch remixed. The white version of this has a tendency to late crazing which is a pity because I really like the creamy surface of this.

Earthenware tests 10/2/18

AB Clear glaze Frit Eckalite LB revised to use Strontium carbonate LB revised to use Whiting


 

Five Earthenware Base Recipes

Originally written 26 Sept 2016

Testing of five different Cone 04 matte or satin base recipes. All of the recipes have very similar ingredients, but different ratios.

These tests weren't ultimately successful as a week later four of them had crazed.

Retesting Julie's Satin (JMBC) and also testing a variation (JMBC revA), revised using hints from Glaze Simulator.

 A. Jackie's Matte via Priscilla Hollingsworth

38  Gerstley borate
10    Lithium carbonate
5    Nepheline syenite
5  Eckalite 2
42  Silica

5% Zircosil



B. Satin Base (from here)

65.5 Ferro frit (4124) 3124
11    Nepheline syenite
5      Eckalite
42    Silica

C. Julie's Satin (from here)

27  Gerstley borate
7    Lithium carbonate
17  Whiting
4    Nepheline syenite
11  Eckalite 2
34  Silica

 D. Hirsh's Satin Matte

32  Gerstley borate
9    Lithium carbonate
17  Whiting
4    Nepheline Syenite
4    Eckalite 2
35  Silica

2% Bentonite

 E. Julie's Matte revised to fix crazing (JM rev A)

27  Gerstley borate
6    Lithium carbonate
17  Whiting
4    Nepheline syenite
12  Eckalite 2
34  Silica